The present invention relates to disc refiners, and more particularly, to an improved method and apparatus for rotating the discs of a double disc refiner.
Double-disc refiners have been utilized for many years to refine pulp and similar material by subjecting the pulp to the heat and stresses generated as the pulp passes radially through closely spaced, counter-rotating discs. The typical drive speed for the discs in North America, is 1200 rpm. It is known, however, that operation of a double disc refiner at 1800 rpm reduces energy consumption by approximately 20 percent to produce the same freeness in the refined product as rotation at 1200 rpm. This energy benefit is reduced, however, by the substantial equipment cost increase associated with driving both discs at 1800 rpm.